BG65970B1 - Microsystem for measuring the three magnetic field components - Google Patents

Abstract

The microsystem for measuring the three magnetic field components comprises a square mixed-conductivity-type semiconductor pad (1). At the four ends of one of its sides there are consecutively formedidentical ohmic contacts û first (2), second (3), third (4), and fourth (5). The first (2) and the third (4), respectively the second (3) and the fourth (5) ohmic contacts are diagonally arranged. The magnetic field (6) is arbitrarily directed with respect to the pad (1). With three consecutive combinations of coupling of the contacts, each of them containing two ohmic contacts connected to a current source (7) and respectively the other pair of contacts as an output, consecutive measuring is performed of the three mutually perpendicular components of the magnetic field û the first (8), second (9), and third (10). The second (3) and the third (4) ohmic contacts are the output (11) for the component (8), the third (4) and the fourth (5) ohmic contacts are the output (12) for the component (9), and the second (3) and the fourth (5) ohmic contacts for the component (10).

Description

The invention relates to a microsystem for measuring the three components of a magnetic field, and in particular to a microsystem for sequentially measuring the three components of a magnetic field, applicable in the field of sensor electronics, control technology and low-field magnetometry, contactless automation, microsystems, microsystems field topology near magnetic surfaces (permanent magnets, flaw detection, biomagnetism), medicine, energy, automotive, object positioning and in space, military and others.

BACKGROUND OF THE INVENTION

A microsystem is known for sequentially measuring the three components of a magnetic field containing a rectangular semiconductor substrate of impurity conductivity, on one plane on which seven contacts are formed - first and second bases, which are identical and rectangular in shape, located to the short sides of the substrate, and in the area between the bases there is an emitter and four identical rectangular collectors - first, second, third and fourth. The emitter is near the first base and is in the middle, at the width of the substrate, near the emitter and the first base along the long sides of the substrate are located the first and second collector, and near the second base and along the long sides of the substrate are the third and fourth collectors. The distance between the first and second and respectively between the third and fourth manifolds is as long as the bases. The emitter through the first current generator is connected in a straight direction to the second base, the two bases are connected is the second current generator so that the polarity of the emitter and the first base coincide. The external magnetic field is in any direction relative to the substrate. With three consecutive collector connection combinations so that each contains two pairs of collectors, which through a resistor and a third current source are connected in reverse direction to the second base, three outputs are defined for sequential measurement of the perpendicular components of the magnetic field - first, second and third. The outputs for the first component of the magnetic field are the two common points of connection of the first and fourth and respectively the second and third manifolds, the output for the second component are the common points of connection of the first and third and respectively the second and fourth manifolds, and the output for the third component, the common points of connection of the first and second and respectively of the third and fourth manifolds [1].

The disadvantages of this microsystem for the measurement of the three components of the magnetic field is the complex construction, comprising seven contacts and three current sources, and its increased dimensions leading to low spatial resolution.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a microsystem for measuring the three components of a magnetic field of simplified construction and small dimensions.

This problem is solved by a microsystem for measuring the three components of a magnetic field containing a square semiconductor substrate with impurity-type impedance, the same ohmic contacts of the first, second, third and fourth as the first and the third, and respectively the second and fourth are arranged diagonally. The external magnetic field is in any direction relative to the substrate. With three successive combinations of contacts, each of which contains two ohmic contacts connected to a current source and the other pair of contacts respectively, the outputs of the three mutually perpendicular components of the magnetic field are measured, first, second and third. The output for the first component is the second and third ohmic contact, and the first and fourth are connected to the source, the output for the second component is the third and fourth, and the first and second contact

65970 ΒΙ are connected to the source, and for the third component - the second and fourth, and the first and third contacts are connected to the source.

Advantages of the invention are the simplified construction containing only a four-pin substrate and one power source, and the small dimensions allowing substantial miniaturization of the microsystem leading to high spatial resolution.

Explanation of the annexed figures

The invention will be further explained with the accompanying drawings, where:

Figure 1 is a construction of a microsystem for measuring the three components of a magnetic field;

Figures 2,3 and 4 show the three different combinations of connecting the ohmic contacts to the current source and the outputs for sequential measurement of the perpendicular components of the magnetic field.

Examples of carrying out the invention

The microsystem for the measurement of the three components of the magnetic field contains a square semiconductor substrate 1 with impurity conductivity, clockwise identical ends 1, 2, 3, 4 and 4 in the four ends as the first 2 and the third 4, and respectively the second 3 and fourth 5 are arranged diagonally. The external magnetic field 6 is in any direction relative to the substrate 1. With three successive combinations of connecting pins 2,3,4 and 5, each of which contains two ohmic pins connected to current source 7 and respectively the other pair of pins as output are measured in series. the three mutually perpendicular components of the magnetic field - first, 8, second 9 and third

10. The output 11 for the first component 8 is the second 3 and the third 4 ohmic contact, and the first 2 and the fourth 5 are connected to the source 7, the output 12 for the second component 9 is the third 4 and the fourth 5, and the first 2 and the second 3 contact are connected to the source 7, and for the third component 10, the second 3 and fourth 5, and the first 2 and third 4 contacts are connected to the source 7.

The action of the microsystem to measure the three components of the magnetic field according to the invention is as follows. When two of terminals 2 and 5, 2 and 3 or 2 and 4 are connected to the current source 7, a current of 1 ₂₅ , 1 _{2 3} or 1 _{2 4} occurs in the volume of the square semiconductor substrate 1. The effective trajectory of the carriers, due to the planarity of the power contacts at the three connection combinations 2 and 5, 2 and 3, and 2 and 4, is curvilinear (the trajectory begins and ends on the upper surface of the pad 1). As a result of the equipotentiality of the ohmic contacts 2, 3,4 and 5, initially the current lines are perpendicular to the upper side of the substrate 1 with the contacts 2, 3,4 and 5, figure 1. Therefore, in this particular part of the trajectory of the carriers, the vertical component of their drift velocity Y ^, Y _y ~ and the current penetrates deeply into the active sensor zone, in this case the pad 1. In this case, the directions of velocity vectors Y _y under the two power contacts 2 and 5, 2 and 3, or 2 and 4 are opposite. On the trajectory between the supply contacts 2 and 5, 2 and 3, or 2 and 4, there is a region dominated by the horizontal component W _b of the carrier velocity V parallel to the plane of the substrate 1, Y _b - ν ^. In the other sections of the velocity current lines Y ^, determine the vertical y _y and the horizontal y _b component, y _l =

V + W.

ν b

In the presence of the external magnetic field B 6 with the orthogonal components B _x 8, B _y 9 and Β _ζ 10, Lorentz P forces corresponding to the interaction of the components 8, 9 and 10 with the vertical y _y and the horizontal y _b velocity of the carriers are generated simultaneously. . The vector sum of the components Β _χ 8, B _y 9 and Β _ζ 10 determines the magnetic vector B 6, i.e. B = B _x + B + Β _ζ and its value is | B | = (Β _χ ² + Wu ² + Βζ ² ) ^{ι / 2} . The deflection forces of Lorentz P _b are simultaneously perpendicular to both the magnetic components B _x 8, B 9 and Β _ζ 10 and the velocities Y _y and Y _b . It is these lateral (lateral) Lorentz deviations of the moving carriers that cause the Hall effect to be generated on the upper boundary surface of the semiconductor substrate 1, where the contacts 2, 3, 4 and 5 are, i. there arise additional

65970 B1 electric loads, respectively the Hall E _{n field} and the voltage at Hall Y _n . With a fixed supply current of 1 ₂₅ = const 1 ₂₃ = sop51 and 1 ₂₄ = SOP31 Hall voltages are linear and odd functions of the magnetic components Β _χ 8, B 9 and Β _ζ

10. The measurement of the Running Signals gives unambiguous information about the magnetic components 8, 9 and 10.

The unexpected positive effect of the technical solution, in comparison with the known one, is that such a microsystem instrument design has been created, which allows with sequential combinations of connecting a minimum number of contacts 2, 3, 4 and 5, ie. only 4, extract all the information in the form of linear and odd Running Voltage for the respective orthogonal component B _x 8, B _y 9 and Β _ζ 10 of the magnetic field B 6. This information contains both the value of the magnetic component 8.9 or 10 , and its sign, respectively, the direction. The first magnetic component B _x 8 is measured at the output 11 with the Hall voltage H _{nz 4} (B _x ), i. E. the voltage between the second 3 and the third 4 ohmic contact at a constant supply current 1 _{2 5} = sop51, figure 2. The origin of the signal H _{nz 4} (B _x ) is the result of the opposite vertical velocities Y _y and - Y _y of the carriers below the supply first 2 and 4 contact 5. Their corresponding Lorentz deflection forces are also opposite and a voltage of Hall U _{nz 4} (B _x ) is generated on the surface region at the output contacts 3 and 4. It is uniquely related to the first component B _x

8. The second magnetic component B _y 9 is measured by the following combination of connections - the power contacts are the first 2 and the second 3, and the output 12 are the third 4 and the fourth 5, figure 3. The origin of the Hall voltage H _{H 4 5} (B _y ) is the same as that already described for the first component B _x 8. The third magnetic component Β _ζ 10 is measured by the third combination of connecting power contacts are the diagonal first 2 and third 4 and the output 1 3 are the other two diagonal contacts 3 and 5, 4. The Hall voltage V _{H 2 4} (B) is generated from the horizontal component Y _L velocity U ^ of the charge carriers.

The problem of the parasitic effect on the output 11, 12 or 13 of the other magnetic components for which it was not intended was also overcome originally. The solution lies in the appropriate choice of output contacts. For example, if the component Β _χ 8 is measured, on the output 11, the other two components B _at 9 and Β _ζ 10 generate simultaneously common-mode components (potentials with the same sign and equal in value). Since the output 11 is differential, the parasitic potentials compensate for and do not change the useful Hall voltage H _{nz 4} (B _x ) in this case. Similarly, the negative influence of the components B _x 8 and Β _ζ 10 on the output 12 is compensated. on the Hall voltage Y _{H4 5} (B _y ), which is the component B _y 9. The effect of the components B _x 8 and B _y 9 is measured by the corresponding Lorentz forces on the differential output 13, respectively, on the Hall voltage H _{h 5} ( Β _ζ ), is also in-phase and practically does not change.

The conversion efficiency of the respective magnetic components 8.9 and 10 in Hall voltages 11, 12 and 13 for the different channels differs at the same supply current 1 _{2 5} = 1 _{2 3} = 1 _{2 4} = const. Their alignment, simplifying the subsequent processing of sensor signals, can be achieved by establishing different supply currents 1 _{2 5} , 1 ₂₃ and 1 ₂₄ . To achieve high efficiency transducer substrate 1 must have a ptip conductivity, since the mobility of electrons ppsgo _n is greater than that of the holes.

The solution of the technical problem with only semiconductor pad 1, four contacts and one current source significantly simplifies the known microsystem for sequential measurement of components 8, 9 and 10 of the magnetic field B 6. At the same time, the dimensions of the new magnetometer are significantly reduced and its separation is increased ability. Essentially, information about the three components of the magnetic field B 6 is extracted from the same "point" in space. Another advantage is the technological simplification in the implementation of the microsystem, since it is not necessary to form diode p-n junctions for the emitter, collectors, etc. The switching of the functions of contacts 2, 3, 4 and 5 from the power supply to the measurement, or vice versa in the sequential measurement of the components 8, 9 and 10 can be carried out by means of a fixed frequency multiplexer. The frequency is determined by the possible dynamics of the measured magnetic field B 6. The inevitable

65970 B1 offset (the parasitic voltage of the outputs 11, 12 and 13 in the absence of a magnetic field B 6) can easily be compensated for in the next stage of the Hall voltage processing.

The possibility of increasing the sensitivity of the new sensor is the use of cryogenic media, such as liquid nitrogen, liquid neon, etc. At low temperatures, the mobility of the carriers of the carriers increases many times. This leads to a sharp increase in the drifts speed of electrons, hence high deflective forces Lorentz P _L and the Hall effect, and thus magnitochuvstvitelnostga the individual channels.

The preferred technologies for implementing the new microsystem for measuring the three components of the magnetic field are CMO5, ΒϊΟΜΟδ, or micromachining processes. They provide an optimal opportunity for integration into a common silicon chip of the magnetometer together with the output signal processing circuits 1C. Such intelligent microsystems are multifunctional.

Claims (1)

1. A microsystem for measuring the three components of a magnetic field containing a semiconductor conductor with impurity type impedance, on one side of which ohmic contacts, a current source, three outputs are formed, with three successive combinations of contact connections measuring the three mutually perpendicular components in a magnetic field with an arbitrary direction to the substrate, characterized in that the substrate (1) is square, at its four ends on one side are formed in a uniform clockwise direction. your ohmic contacts first (2), second (3), third (4) and fourth (5), the first (2) and third (4), and respectively the second (3) and fourth (5), are diagonally, the output (11) for the first component (8) of the magnetic field (6) are the second (3) and third (4) ohmic contacts, and the first (2) and fourth (5) are connected to the source (7), the output (12) ) for the second component (9) are the third (4) and the fourth (5), and the first (2) and the second (3) contact are connected to the source (7) and the outlet (13) for the third component (10) is the second ( 3) and the fourth (5) contact, and the first (2) and third (4) are incl enes to the power source (7).